SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fcf0380a2e80ccd667eba2c57579c569c4f55b09569cd336bca63fef9412740a' 
  AND token = 'rYMWN0TdQH5GXiLvPfgakpfEztDTHvccCvbNIJqxGpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}